The National Transportation Safety Board will hold hearings Oct. 22 and Oct. 23 as part of its ongoing investigations of two Metro-North Railroad accidents.

Both accidents, on May 17 and May 28, occurred on the New Haven line in Connecticut. The July 18 derailment of a CSX freight train on Metro-North's Hudson line in the Bronx isn't included in the hearings but remains the subject of another NTSB investigation. The derailment snarled commuter rail service for 12 days.

On May 17, an eastbound Metro-North train derailed in Bridgeport and then was struck by a westbound Metro-North train. Some 73 passengers and three crews members from the two trains were taken to local hospitals with injuries. There were no fatalities.

On May 28, a Metro-North track foreman was struck and killed by a Metro-North train in West Haven. Two traffic controllers, one of whom was an apprentice, had taken the section of track where the foreman was working out of service at his request. However, the student controller removed the electronic block about an hour later without the knowledge of the senior controller or the foreman.

In June, the NTSB recommended Metro-North provide redundant protection for track maintenance crews who depend on controllers for signal protection.

The hearings will include testimony about track inspection and maintenance, passenger car safety standards and crash-worthiness, policy and practice on worker protection and organizational safety culture.

The NTSB said it will release determinations of the probable causes for the two accidents after its investigations, including the hearings, are completed.